Universal joint having one center of deflection



Feb. 5, 1952 J. T. WELSH 2,584,648

UNIVERSAL JOINT HAVING ONE CENTER OF DEFLECTION Filed Nov. 16, 1946 I INVE R. L/a/y/v 7 W545 iY LI Kv-Ze AW arrap/vzys' Feb. 5, 1952 J. T. WELSH 2,584,648

UNIVERSAL JOINT HAVING ONE CENTER OF DEFLECTION Filed Nov. 16, 1946 5 Sheets-Sheet 5 7 i 4 #5 T c].7-

I Jay/v 7 Patented Feb. 5, 1952 r-Eo STATES .sra r OFFICE UNivERs-An..iomr nAvliieioNe-omvrna f V .1011 DEFLECTION- iron- T; Welfsli, Iranians: Park", N. a; ma a WeI'slr-executrixofj said Jol'flrT. welsh; de-- ceased Applieatiori November 16, 1946, sei iz il io. 710,25

- 3'Claiins'. (81.64421 lThi'si invention relates to universal joints and more particulariyto universaljoir'itshaving' one center of deflection; such that the speed of the drivenshaft is at all times the same as that'of the driving shaft. 7 I, 'Inthe ordinary tyne o rigid universal joint or Hbokes coupling, where the driven .shaft'isar ranged at an angle with respect tothe driving the'speedof the driven shafthvaries from a maximum to a minimum or vice'versa durin'gf eachone-quarter revolution. For instance, 'y'vheie theidriven shaft is'arranged at an angle one withresbect tothe driving shaft and the latter shaft is driven "at asp'eedof 500 P. ML, the

maximum velocity Iof. the driven shaft Willh G8 PI M'. and" they minimum 492 P. mak ng a variation bf'lGfR. P. M. during each one-quarter revolution. As the angle between the driving shaft and the 'drivenfshaft increases, the; variation in speed is correspondingly increased. In the case of automobile transmissions, thisresults not only in increased frictionupon the bearings of the universal'joint but also inthe' imposition of severe strains upon the gears with which the driven shaft is connected'and upon thefiy-Wheelofthe driving shaft. I

I In the ordinary type of rigid universal joint, onHooh's coupling, wherethe driven shaft is arranged at an 'ang'le' with resii ect to the driving shaft, the speed of the driven shaft varies from a maximum to a minimum, or vice versa, during each one-quarter revolution. The reason for this is that the trunnions, on which thejshaft" of each fork pivots travel in a plane at right angles to the axis of its respective shaft. These planes biseet each other along a line at right angles to the axes of the two shafts. When the trunnions in eithe'r ifork are on the aforesaid bisectirlg line, the shafts are in phase. This occurs four times in each revolution. Between these four points in each revolution, there occurs a variation in the angular velocity .of the two shafts. 'lfhusyw hen the drive shaft is rotating at constant angular velocity' with ten degreesarigularityhetween the axes'of the 'tvvofsha'fts, the driven shaft'will lag one degree and twenty two minutes-behind the drive shaft, after the drive] shaft has rotated fortr-five degrees beyond the point where the shafts were inphase; and will he" pha'se' again after rotating through. another forty-five dgrees. In rotating throfi'gh the next ninety degrees, the driven shaft willf'gain one degree and twenty-two minutes in the first forty five degree rotation, and will. be in phase again after rotating an additional forty-five degrees. This accounts for the speed variations noted above! If the angularity between the shafts'is twenty degrees, a corresponding lag and lead in driving shaft l2. Disposed within this member;

each ninety degreesof revolution will be fivede {n eces and foi-ty ei'ght minutes, and at forty 'd'e grees .a'ngularity', twenty-one degrees and forty minutes. I In the "new 'jfoihtliisolosed' hereinafter; ithe bevel pinion and ioll'erstravel' in a piane'whichbisects the angle hetvveen'the axesofth'e drive and driven shafts so that the shafts are always inbhase and the angular velocity betweentlie tvvo i's constant, regardless of the singularity he-' tween thetvvoshafts. While ten degree 'angu-' lai-ity was used to illustrate the diiferenee inthe functioning" of "the two universalj oints', the new joint-will transmit power at aptireciaflole speeds with uniform motiornvlieii there are other anew ia'rit'ies Within the usual" range, between the axes of the two shafts;

Accordingly, one object of this" invention is to rovide a universalfljoint having one center of deflection' such that the driven and' driving shafts constantly rotate at thesame s 'ciee'd. f Another object ofthi's' invention is to provide such a universal joint in which one center of defiection is obtained hy'as'im'ple" yet positive act-f ing means.

Another objector thisinvention' is to provide such'a univer's'al'joint which is simple, eompac't, of'rel'ativel'y' lightweight; and easily assembled and disassembled; v Otheran'd further objects of this invention will appear "during tiie eourseof the following description when taken with the accompanying drawings in which V v Fig; I is a cross section'a'l view of one embodimerit oftliis' irivention.

Fig.2 i'sa erossi sectionai view througlrplane Ill-II of'Fi'g; 1 with the driving and driven shaftsiri' axial'alig'nment; Fig. 3 is'a developed viewal'ozig' line III-1110f Fig.1; j Q

Fig. '4; isa' cross-sectional view showing thees sential portions of an alternativeembodiinent of this invention:

5955 is a schematic Gross-sectional viewshowing'the essential elements of another alternative embodiment of this invention; s

Fig. 6 is a schematic" cross sectional through" plane VIf-"-VI of Fig. 5-: and I Fig.- 7- isa schematic cross sectional vie'w'sl'm ilar to tliatof Fig". 6 showing still another em bodiinentof this invention. In 'ig'. I'is's'hown an outer substantiall spherically shaped member. H centered on the endof view H isa similar substantially" spherically shaped inner member l3 centered on the enciofdriven shaft-M. Member Hi is-suitably cut away as shown in order to allows-heft M to extend therethrough and shafts I2 and M are. rigidlyseeured to ir iembers H and-i3 respectively by any Suit!- able means such as keying, splining or welding. The axis of shaft I4 is shown at an acute angle C with the axis of shaft I2, this being the maximum deviation angle possible for the embodiment illustrated but this, of course, can be varied at will within reasonable limits by proper design of the joint. Disposed within member I3 is a sub stantially spherical ball I5, and a beveled toothed 4 gear It provides the common center of deflection between members II and I3, there has been disclosed in Figs. 1 and 2 a positive action means which insures that as the axes of shafts I2 and I I are displaced one from the other, gear I6 will move to a position such that plane 11-11 (Fig. 1) through its axis bisects the obtuse angle between shafts I2 and I4, forming the two equal angles roller or gear I6 is rotatably secured as by means of pin I! at a point on the peripheryof ball I5, gear I6 extending throughcooperating'longitudinal slots cut in members I I and I3 and forming races as shown. By the term longitudinal as used here and hereinafter in this specification is meant substantially in a plane including the driving and driven shafts or a plane parallel to that plane. The detailed construction of these slots is shown more clearly in Figs. 2 and 3. The beveled surfaces of gear .l6 are preferably cut to coincide with arcuate planes described by radii extended from the center of the universal joint, and the axis of rotation of gear I6 coincides with a radius extended from the center of the joint as shown. Surrounding the joint thus far described are means for sealing the joint for ease of lubrication, comprising a substantially spherical shell I8 shown in two halves connected by means of a screw joint, shell i8 being rigidly held with respect to member II and shaft I2 and cut away as shown to allow relative movement of member I3 and shaft I4. Surrounding shell I8 is a second sealing shell I9 rigidly held with respect to shaft I I and sealed at its end opposite shaft I4 by means of packing member 20 and threaded sealing ring 2| as shown. A lubrication connection 22 is provided extending through shell I9.

In Fig. 2 it has been assumed that shaft I4 of Fig. 1 has been moved relative to shaft I2 so that both shafts are in axial alignment in order to show the manner in which members II and I3 and ball l5 are cut away for ease of assembly of the joint and the manner in which gear I6 insures a positive acting single center of deflection between members II and I3. The sides of ball I5 are machined away to form parallel faces as shown and member I3 is machined away sufficiently to allow the placement of ball IS within member I3 in a position 90 away from that shown, ball I5 then being rotated 90 into the proper position. Member I3 is also machined to provide two parallel faces 25 in a plane perpendicular to those machined for the entry of ball I5, and outer member II is suitably cut away as shown in Fig. 1 to allow the entry of member I3 when it is turned 90 away from the position illustrated, being rotated thereafter into the proper position during assembly. The slot provided in outer member II for the entry of gear I6 has a toothed race 26 provided on one side which engages the teeth of gear I6 and the other side of the slot is cut away as at 21 so that it does not bear against gear I6. Similarly the opposite wall of the corresponding slot of inner member I3 is formed into a toothed race 28 to engage the teeth of gear I6 and the opposing wall is cut away as at 29 so that it does not touch gear I6. When ball I5 and members II and I3 have been assembed together and rotated into their proper positions, gear I6 can then be dropped through the corresponding slots of members I I and I3 into the position shown, then being rotatably secured to ball I5 by means of pin I! which extends through gear I6 into ball I5. Sealing shells I8 and I9 can thereafter be slipped over the unit as shown tocomplete the assembly. Thus, since A and B (Fig. 1). It is, of course, obvious that ball I5 and pin I! are not essential to the operation of this embodiment of this invention and can be dispensed with in a particular joint if desired. Similarly, sealing shells I8 and I9 are not necessary and may be dispensed with in case a sealed lubricated joint is not required.

In Fig. 3 is shown in a flattened-out developed view in more detail the manner in which gear I6 meshes with the'corresponding races 26 and 28 provided on the opposite face of the slots of members II and I3 respectively.

In Fig. 4 is shown a cross-sectional view of another alternative embodiment of this invention. Lubricating sealing members similar to those shown in Fig. 1 have been omitted for the sake of clarity of the drawing. Similar com- I ponents of the units of Figs. 1 and 4 have been I axial aperture of gear I6. The other end of member 3I extends through an axial aperture of roller 30 so that any circumferential motion of gear It in a plane including shafts I2 and I4 will be transferred immediately to roller 30.

Roller 30 is snugly fitted against the sides of the slots shown in members II and I3 so that as it rolls over them in the operation of the universal joint, a good bearing contact surface with each is maintained at all times to transmit rotary motion of the joint therebetween. Thus, it is apparent that the universal joint of Fig. 4 is'adapted to transmit larger torques and powers than that of Fig. 1.

In Fig. 5 is shown in cross-sectional view still another embodiment of a universal joint according to this invention. Again, the lubricating sealing members of Fig.1 have been omitted for the sake of clarity of the drawing. This universal joint is intended to transmit even larger amounts of power than that for which the joint of Fig. 4 is designed, and as shown it differs from that of Fig. 1 in that three beveled toothed rollers It are utilized to transmit power between members II" and I3. The spatial relation of these three toothed rollers I6 is shown more clearly in Fig. 6. A longitudinal slot in memher I I" and a cooperating longitudinal slot in member I3" provide races for each roller I6 as shown, and each beveled roller I6 has ap proximately its center third portion cut'to form a toothed gear portion thereat. A corresponding portion of the longitudinal wall of the slot of member II shown has formed on it a toothed rack or race to mesh with the gear portion of J the corresponding roller lIi shown.

In Fig. 6 is shown a cross-sectional view.

through plane VIVI of Fig. 5. which shows with longitudinal wall of the slot of member H" has formed on it a toothed rack as above-described, and the opposite wall of the corresponding slot of member i3" is similarly provided with a toothed rack or race to mesh with the toothed roller 56 as shown, and all other longitudinal portions of the slots in members H and 13" fit snugly against roller l6 to provide a good bearing surface upon which the roller it may roll during operation of the universal joint. Thus, the smooth portions of rollers 16' bearing against the cooperating smooth surfaces of the races of members i l and i3 take the major portion of the thrust between these members as the joint rotates while the toothed portion meshing with the cooperating teeth of the races fixes the relative position of the members to maintain one center of deflection as the joint is flexed during rotation. The three rollers it are spaced equidistant one from the other around the periphery of the universal joint and are connected by a transmission member 35 of the shape shown. A pin extends through an axial aperture of each roller it into a corresponding aperture in member so that each roller 56' is rotatable upon its pin 36. Thus, the power is transmitted between the halves of the universal joint by means of three rollers instead of one and each roller is of a heavy duty type since it provides a bearing area over a large portion of its surface as above-described. It is, of course, obvious that transmission member 35 and pins 36 are not essential to this embodiment since each roller it is in itself a positive acting device because its center toothed portion meshes with the opposing toothed racks of the cooperating slots of members H and 13''.

Figs. 5, 6 and '7 are schematic cross-sectional views of my universal joint. In these views, I have not disclosed how the two spherical concentric members may be assembled. It is understood, however, that they may be assembled in various ways, one of which is shown in the Fetzer patent, 1,021,923, issued April 2, 1912.

In Fig. '7 are illustrated the details of another alternative embodiment similar to that illustrated in Figs. 5 and 6. Here instead of using three similar toothed rollers 15, one beveled toothed roller [6 and two beveled smooth surfaced rollers 39 are used, one toothed rack then being provided over the entire surface of one side of the slot of member I I l and a corresponding toothed rack being provided on the opposite face of the cooperating slot of inner member H3. Rollers 39 and gear [6 are then connected together in a unit in a similar fashion to that illustrated in Fig. 6 by means of transmission member 35 and pins 36. As shown, the slots provided in members iii and H3 for rollers 30 fit snugly against the surface of these rollers in order to provide a good bearing surface as the rollers 36 rotate during the operation of the universal joint.

The terms snug and snugly as used throughout the foregoing are intended to mean that the parts are free from intended lateral play and not that they fit so tightly as to make the invention inoperative. Thus, the rollers must slide in the slots shown and described while being snug or free from excessive lateral motion,

excepting to the extent usually encountered in the case of sliding bearing arrangements made in accordance with currently common machine designing practices. For example, some space must be provided between the sliding parts to provide room for a lubricant therebetween.

Numerous additional applications of the abovedisclosed embodiments will appear to those skilled in the art and no attempt has been made to exhaust such possibilities. The scope of the invention is defined in the following claims.

What is claimed is:

1. A universal joint adapted to couple driving and driven shafts including in combination, a substantially spherical member on each adjacent end of said shafts, said spherical members being disposed one within the other, three longitudinally disposed beveled races spaced equidistant one from the other around the periphery of said spherical member of said driving shaft and each disposed in a plane including said driving shaft, three cooperating opposing longitudinally disposed beveled races spaced equidistant one from the other around the periphery of said spherical member on said driven shaft and each disposed in a plane including said driven shaft, each of the races on each of the spherical members being wholly within the spherical members and having side Walls and closed ends, each of the beveled races in the inner spherical memhere being aligned With the beveled races in the outer spherical member, a transmission member freely mounted within the spherical member on the driven shaft having three arms extending radially outwardly from the center thereof, beveled rollers rotatably mounted on each of the arms of the transmission member, each of the rollers being disposed within a cooperating pair of the beveled races in each of the spherical members, at least one of said rollers having beveled teeth on its periphery, at least one of the beveled races in the outer spherical member having beveled teeth on one of its side walls, the cooperating beveled race in the inner spherical member having beveled teeth on its side wall opposite to the toothed side wall of the beveled race in the outer spherical member, the toothed roller being disposed within the beveled race and meshing with the teeth on the opposed walls "of the beveled race, whereby said rollers roll along their respective cooperating beveled races and teeth as said joint is flexed to produce one center of deflection of said joint.

2. A universal joint as set forth in claim 1 wherein each of the rollers have a toothed portion meshing with the opposing teeth of each of the races and a smooth portion bearing against the cooperating plain surfaces of the races.

3. A universal joint as set forth in claim 1 wherein one of the rollers has teeth extending radially throughout its entire periphery, the opposing side Walls of one of the races having teeth extending radially thereof throughout its entire length and the side Walls of the other races and the beveled rollers having plain surfaces cooperating with each other.

JOHN T. WELSH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,440,648 Thiemer Jan. 2, 1923 1,625,410 De Ram Apr. 19, 1927 1,626,270 Craun Apr. 26, 1927 1,728,949 Weiss Sept. 24, 1929 2,236,633 Wingquist Apr. 1, 1941 

